Combining 123I-Metaiodobenzylguanidine SPECT/CT and 18F-FDG PET/CT for the Assessment of Brown Adipose Tissue Activity in Humans During Cold Exposure
Combining 123I-Metaiodobenzylguanidine SPECT/CT and 18F-FDG PET/CT for the Assessment of Brown Adipose Tissue Activity in Humans During Cold Exposure
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DOI：
10.2967/jnumed.112.111849
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发表时间：
2013-02-01
影响因子：
9.3
通讯作者：
Verberne, Hein J.
中科院分区：
文献类型：
--
作者：
Admiraal, Wanda M.;Holleman, Frits;Verberne, Hein J.
棕色脂肪组织(BAT)已经成为研究的焦点，希望找到对抗肥胖的新靶点。F-18-FDG PET/CT可显示代谢BAT活性。此外，用放射性标记的去甲肾上腺素类似物I-123-间碘苯基胍(I-123-MIBG)可以观察到蝙蝠的交感神经支配。我们的目的是确定I-123-MIBG SPECT/CT和F-18-FDG PET/CT在成人中是否识别与活跃的BAT相同的解剖区域。此外，我们调查了通过这些技术测量的BAT活动的大小是否相关。最后，我们试图建立I-123-MIBG注射和随后的SPECT/CT采集之间的最佳时间间隔，以可视化BAT的交感刺激。方法：10例体重指数为19~25 kg/m(2)的健康高加索男性(年龄18~32岁)，在2wk间隔内接受1次F-18-FDG PET/CT扫描和2次I-123-MIBG-SPECT/CT扫描。在两个不同的情况下，受试者在隔夜禁食后暴露在温和的寒冷(17摄氏度)中2小时。冷暴露1h后，分别给予F-18-FDG(1次)或I-123-MIBG(其他情况)。F-18-FDG注射后1h行F-18-FDG PET/CT检查，I-123-MIBG注射后4h和24 h行I-123-MIBG-SPECT/CT检查。结果：在注射I-123-MIBG后4h的SPECT/CT扫描和注射I-123-MIBG后24 h的SPECT/CT扫描中，10名受试者中有8人在BAT中观察到F-18-FDG摄取，而I-123-MIBG摄取在7人中观察到。所有在BAT中显示I-123-MIBG摄取的受试者在BAT中也显示F-18-FDG摄取。给药后4h F-18-FDG的最大标准摄取值与I-123-MIBG的半定量摄取之间无统计学意义的相关性。在给药后24 h，F-18-FDG的最大标准摄取值与I-123-MIBG的半定量摄取呈正相关(r=0.64，P=0.04)。结论：I-123-MIBG SPECT/CT和F-18-FDG PET/CT作为交感神经活性的标志物和F-18-FDG PET/CT作为代谢活动的标志物，与活性BAT具有相同的解剖区域。此外，当在注射I-123-MIBG后24小时进行I-123-MIBG SPECT/CT时，用这些技术测量的BAT活动的大小具有很强的相关性。这一发现不仅支持人的BAT活动受到交感神经的影响，而且证实了I-123-MIBG SPECT/CT是一种可视化和量化BAT交感神经刺激的方法。
Brown adipose tissue (BAT) has become a focus of research in the hope of finding a new target to fight obesity. Metabolic BAT activity can be visualized with F-18-FDG PET/CT. Furthermore, the sympathetic innervation of BAT can be visualized with the radiolabeled norepinephrine analog I-123-metaiodobenzylguanidine (I-123-MIBG). We aimed to determine whether I-123-MIBG SPECT/CT and F-18-FDG PET/CT identify the same anatomic regions as active BAT in adult humans. Furthermore, we investigated whether the magnitude of BAT activity measured by these techniques correlated. Finally, we tried to establish the optimal time interval between I-123-MIBG administration and subsequent SPECT/CT acquisition to visualize sympathetic stimulation of BAT. Methods: Ten lean (body mass index, 19-25 kg/m(2)), healthy Caucasian men (age, 18-32 y) underwent one F-18-FDG PET/CT and two I-123-MIBG-SPECT/CT scans within a 2-wk interval. On 2 separate occasions, the subjects were exposed to mild cold (17 degrees C) for 2 h after an overnight fast. After 1 h of cold exposure, F-18-FDG (one occasion) or I-123-MIBG (other occasion) was administered. F-18-FDG PET/CT was performed at 1 h after F-18-FDG administration, and I-123-MIBG-SPECT/CT was performed at 4 and 24 h after I-123-MIBG injection. Results: F-18-FDG uptake in BAT was observed in 8 of 10 subjects, whereas I-123-MIBG uptake was observed in 7 of 10 subjects in both the SPECT/CT scans acquired at 4 h after I-123-MIBG administration and the SPECT/CT scans acquired at 24 h after I-123-MIBG administration. All subjects who showed I-123-MIBG uptake in BAT also showed F-18-FDG uptake in BAT. There was no statistically significant correlation between maximal standardized uptake value of F-18-FDG and semiquantitative uptake of I-123-MIBG at 4 h after administration. However, a positive correlation was found between the maximal standardized uptake value of F-18-FDG and semiquantitative uptake of I-123-MIBG at 24 h after administration (r = 0.64, P = 0.04). Conclusion: I-123-MIBG SPECT/CT, as a marker of sympathetic activity, and F-18-FDG PET/CT, as a marker of metabolic activity, identified the same anatomic regions as active BAT. Moreover, when I-123-MIBG SPECT/CT was performed at 24 h after I-123-MIBG administration, the magnitude of BAT activity measured with these techniques correlated strongly. This finding not only supports that BAT activity in humans is sympathetically influenced but also identifies I-123-MIBG SPECT/CT, when performed 24 h after I-123-MIBG injection, as a method to visualize and quantify sympathetic stimulation of BAT.